Factors Associated with Extraction following Root Canal Filling in Adults

Abstract

Essentially, root fillings are performed to preserve natural teeth. Over time, however, some root-filled teeth will inevitably be extracted. The aim of this historical prospective cohort study in the adult Swedish population was to identify factors associated with extractions within 5 y of registration of a root filling. The cohort consisted of all those whose root fillings had been reported to the tax-funded Swedish Social Insurance Agency (SSIA) in 2009. Demographic data on the individuals registered with a root filling (sex, age, country of birth, disposable income, educational level, and marital status) were received from Statistics Sweden or the SSIA. Dental care setting, tooth type, and any registration of subsequent restorations within 6 mo were received from the SSIA. Multivariable regression analysis was used, and P < 0.05 was considered statistically significant. In total, 216,764 individuals had been registered with at least 1 root filling. Individuals ( n = 824) without complete data were excluded from the analyses. After 5 y, 9.3% of the root-filled teeth had been registered as extracted. Logistic regression analysis found significant associations for all variables except country of birth, disposable income, and educational level. The highest odds ratios for extractions were associated with the type of restoration: teeth with no registration of any restoration and teeth with a direct restoration combined with a post were 3 times more likely to undergo extraction than teeth restored with an indirect restoration combined with a post and core. Overall, high odds ratios for extractions were associated with any type of composite restoration, including composite fillings and crowns combined with or without any post. In summary, after root filling in the Swedish adult population, several individual- and tooth-specific variables were associated with extraction. The reasons for the extractions remain to be studied further.

Patient record assessment of results and related resources spent during 1 year after initiation of root canal treatment in a Swedish public dental organization

“…Following this cohort over time will provide information on long‐term survival of the root filled teeth and eventually also the outcome with respect to the treatment objective of ensuring healthy periapical conditions. The finding that 4 teeth (2.4%), 2 of which were molars, were extracted within the same year as the completed root filling is compatible with findings from register studies in Sweden (Fransson et al, 2016, 2021; Göransson et al, 2021; Kebke et al, 2021). Based on previous epidemiological studies, it may be hypothesized that amongst surviving root filled teeth the incidence of persistent or recurrent apical periodontitis is around 25% (Frisk et al, 2008; Pak et al, 2012).…”

“…Following this cohort over time will provide information on long-term survival of the root filled teeth and eventually also the outcome with respect to the treatment objective of ensuring healthy periapical conditions. The finding that 4 teeth (2.4%), 2 of which were molars, were extracted within the same year as the completed root filling is compatible with findings from register studies in Sweden (Fransson et al, 2016(Fransson et al, , 2021Göransson et Note: The number of appointments includes all appointments for root canal treatment, that is, not only scheduled appointments for instrumentation and root filling but also unplanned emergency appointments, and also for the treatment of teeth which were eventually extracted or cases where root canal treatment had not been completed within the year. The smallest unit analysed was the tooth.…”

“…If dental health continues to improve further and if today's adolescents and young-and middle-aged adults maintain their generally good dental health as they age, there will be less demand for RCTs in Sweden and comparable countries. In a number of studies, various aspects of the complete cohort of root fillings undertaken in Swedish adults in 2009 (n = 248 299 root fillings in 217 047 individuals) have been reported (Dawson et al, 2017;Fransson et al, 2016Fransson et al, , 2021Landt et al, 2018;Markvart et al, 2021;Olsson et al, 2019;Wigsten et al, 2018). These studies were all based on statistics from the SSIA, which continuously registers all dental treatments in adults undertaken by Swedish dentists.…”

“…In a systematic review of tooth survival following RCT (Ng et al, 2010), the pooled proportion of teeth surviving for a 2–10‐year period ranged between 86% and 93%. In a study based on the register of the tax‐funded Swedish Social Insurance Agency (SSIA) of all those whose root fillings had been reported as completed in 2009, 9.3% ( n = 20 255) were subsequently registered as extracted, 5 years after completion of the root filling (Fransson et al, 2021). In the logistic regression model, molar teeth exhibited a twofold odds ratio of being extracted (56.3%, OR = 1.9) compared with the reference tooth group (‘mandibular premolar’; n = 1772, 6.4%).…”

Patient satisfaction with root canal treatment and outcomes in the Swedish public dental health service: A prospective cohort study

“…(Table 3). Studies based on large data registers also show that molar teeth are more frequently extracted (Fransson et al, 2016, 2021).…”